1 files changed, 66 insertions, 0 deletions
diff --git a/packages/integrations/vercel/src/index.ts b/packages/integrations/vercel/src/index.ts
new file mode 100644
index 000000000..49a924b2d
--- /dev/null
+++ b/packages/integrations/vercel/src/index.ts
@@ -0,0 +1,66 @@
+import type { AstroAdapter, AstroConfig, AstroIntegration } from 'astro';
+import type { PathLike } from 'fs';
+import fs from 'fs/promises';
+import esbuild from 'esbuild';
+import { fileURLToPath } from 'url';
+
+const writeJson = (path: PathLike, data: any) =>
+	fs.writeFile(path, JSON.stringify(data), { encoding: 'utf-8' });
+
+const ENTRYFILE = '__astro_entry';
+
+export function getAdapter(): AstroAdapter {
+	return {
+		name: '@astrojs/vercel',
+		serverEntrypoint: '@astrojs/vercel/server-entrypoint',
+		exports: ['_default'],
+	};
+}
+
+export default function vercel(): AstroIntegration {
+	let _config: AstroConfig;
+	return {
+		name: '@astrojs/vercel',
+		hooks: {
+			'astro:config:setup': ({ config }) => {
+				config.outDir = new URL('./.output/', config.outDir);
+				config.build.format = 'directory';
+			},
+			'astro:config:done': ({ setAdapter, config }) => {
+				setAdapter(getAdapter());
+				_config = config;
+			},
+			'astro:build:start': async ({ buildConfig }) => {
+				buildConfig.serverEntry = `${ENTRYFILE}.mjs`;
+				buildConfig.client = new URL('./static/', _config.outDir);
+				buildConfig.server = new URL('./server/pages/', _config.outDir);
+			},
+			'astro:build:done': async ({ dir, routes }) => {
+				const pagesDir = new URL('./server/pages/', dir);
+
+				// Convert server entry to CommonJS
+				await esbuild.build({
+					entryPoints: [fileURLToPath(new URL(`./${ENTRYFILE}.mjs`, pagesDir))],
+					outfile: fileURLToPath(new URL(`./${ENTRYFILE}.js`, pagesDir)),
+					bundle: true,
+					format: 'cjs',
+					platform: 'node',
+					target: 'node14',
+				});
+				await fs.rm(new URL(`./${ENTRYFILE}.mjs`, pagesDir));
+
+				// Routes Manifest
+				// https://vercel.com/docs/file-system-api#configuration/routes
+				await writeJson(new URL(`./routes-manifest.json`, dir), {
+					version: 3,
+					basePath: '/',
+					pages404: false,
+					rewrites: routes.map((route) => ({
+						source: route.pathname,
+						destination: `/${ENTRYFILE}`,
+					})),
+				});
+			},
+		},
+	};
+}